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Commit 1c8cde92 authored by Pierre Ossman's avatar Pierre Ossman Committed by Russell King
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[MMC] sdhci: proper timeout handling 



Use the give timeout clock and calculate a proper timeout instead of using the
maximum at all times.

Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent e16514d8

drivers/mmc/sdhci.c

+44 −3
Original line number Diff line number Diff line
@@ -128,9 +128,6 @@ static void sdhci_init(struct sdhci_host *host) 


	writel(intmask, host->ioaddr + SDHCI_INT_ENABLE);

	writel(intmask, host->ioaddr + SDHCI_SIGNAL_ENABLE);



	/* This is unknown magic. */

	writeb(0xE, host->ioaddr + SDHCI_TIMEOUT_CONTROL);

}



static void sdhci_activate_led(struct sdhci_host *host)
@@ -274,6 +271,8 @@ static void sdhci_transfer_pio(struct sdhci_host *host) 
static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)

{

	u16 mode;

	u8 count;

	unsigned target_timeout, current_timeout;



	WARN_ON(host->data);
@@ -287,6 +286,37 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data) 
	DBG("tsac %d ms nsac %d clk\n",

		data->timeout_ns / 1000000, data->timeout_clks);



	/* timeout in us */

	target_timeout = data->timeout_ns / 1000 +

		data->timeout_clks / host->clock;



	/*

	 * Figure out needed cycles.

	 * We do this in steps in order to fit inside a 32 bit int.

	 * The first step is the minimum timeout, which will have a

	 * minimum resolution of 6 bits:

	 * (1) 2^13*1000 > 2^22,

	 * (2) host->timeout_clk < 2^16

	 *     =>

	 *     (1) / (2) > 2^6

	 */

	count = 0;

	current_timeout = (1 << 13) * 1000 / host->timeout_clk;

	while (current_timeout < target_timeout) {

		count++;

		current_timeout <<= 1;

		if (count >= 0xF)

			break;

	}



	if (count >= 0xF) {

		printk(KERN_WARNING "%s: Too large timeout requested!\n",

			mmc_hostname(host->mmc));

		count = 0xE;

	}



	writeb(count, host->ioaddr + SDHCI_TIMEOUT_CONTROL);



	mode = SDHCI_TRNS_BLK_CNT_EN;

	if (data->blocks > 1)

		mode |= SDHCI_TRNS_MULTI;
@@ -1096,6 +1126,17 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot) 
	}

	host->max_clk *= 1000000;



	host->timeout_clk =

		(caps & SDHCI_TIMEOUT_CLK_MASK) >> SDHCI_TIMEOUT_CLK_SHIFT;

	if (host->timeout_clk == 0) {

		printk(KERN_ERR "%s: Hardware doesn't specify timeout clock "

			"frequency.\n", host->slot_descr);

		ret = -ENODEV;

		goto unmap;

	}

	if (caps & SDHCI_TIMEOUT_CLK_UNIT)

		host->timeout_clk *= 1000;



	/*

	 * Set host parameters.

	 */

drivers/mmc/sdhci.h

+4 −0
Original line number Diff line number Diff line
@@ -125,6 +125,9 @@ 
/* 3E-3F reserved */



#define SDHCI_CAPABILITIES	0x40

#define  SDHCI_TIMEOUT_CLK_MASK	0x0000003F

#define  SDHCI_TIMEOUT_CLK_SHIFT 0

#define  SDHCI_TIMEOUT_CLK_UNIT	0x00000080

#define  SDHCI_CLOCK_BASE_MASK	0x00003F00

#define  SDHCI_CLOCK_BASE_SHIFT	8

#define  SDHCI_CAN_DO_DMA	0x00400000
@@ -156,6 +159,7 @@ struct sdhci_host { 
#define SDHCI_USE_DMA		(1<<0)



	unsigned int		max_clk;	/* Max possible freq (MHz) */

	unsigned int		timeout_clk;	/* Timeout freq (KHz) */



	unsigned int		clock;		/* Current clock (MHz) */

	unsigned short		power;		/* Current voltage */